Electropneumatic switch.



W. M. SCOTT.

ELECTHOPNEUMATIC SWITCH.

APPLICATION FILED JULY 22. 1910.

Patented July 27, 1915.

UNITED STATES PATENT OFFICE.

WILLIAM M. SCOTT, F PHILADELPHIA, PENNSYLVANIA.

ELECTROPNEUMATIC SWITCH.

Application led July 22, 1910.

To all whom it may concern:

Be it known that I, WILLIAM M. SCOTT, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented a new and useful Electropneumatic Switch, ofwhich the following is a specification.

My invention relates to electro-pneumatically controlled switches orcircuit breakers adapted to control circuits carrying heavy electriccurrents, such as used in lighting, power, or other electric systems.

My invention resides in an electric switch or automatic circuit breakerwhich may be restored to normal position (for example, circuit closingposition) by pneumatic power furnished by air cr other suitable mediumunder pressure, operating upon a piston within a cylinder, suitablecontrol means being provided.

My invention resides further in apparatus as described, in which thepiston moves in one direction to restore a switch or circuit breaker tonormal position, and which moves in the opposite direction to trip theswitch or circuit breaker, a suitable control valve being provided whichmay be located at a point more or less remote from the switch or circuitbreaker or which may be controlled by electric energy from a point moreor less remote.

My invention resides in other features hereinafter described andclaimed.

For an illustration of one of the forms my invention may take, referenceis to be had to the accompanying drawing, in which:

Figure 1 is a side elevational view of a switch or circuit breaker withthe pneumatic operating means shown in section, together with adiagramof electrical control circuits. Fig. 2 is a vertical sectional viewthrough a valve. Upon a Ybase or switch-board 1, preferably 'ofinsulating material, such as slate or marble, are secured the mainterminal blocks 2 and 3 of the switch or circuit breaker, the studs 4and 5 electrically communicating, respectively, with the main terminalblocks 2 and 3 adapted to connect them in the circuit to be controlled.A movable contact member 6, representing a laminated bridging member, isadapted to engage and bridge the main terminals 2 and 3 to close thecontrolled circuit. The bridging mem- A Specification of Letters Patent.

Patented July 27, 1915.

Serial No. 573,169.

ber 6 is secured upon the arm 7 pivoted at 8 to the bracket or housing 9secured upon the base 1.

Mounted upon and in electrical communication with the upper terminalblock 2 are the intermediate metallic shunt contact 10 and thestationary shunt carbon contact 11 pivoted at 12 to the bracket 13. Themovable intermediate shunt contact 14 and the movable shunt carboncontact 15 are carried upon the arm 7 and engage, respectively, thecontacts 10 and 11, permanent electrical connection between the contacts14 and 15 and the lower terminal block 3 being maintained by theflexible conductor 16.

Pivoted to the bracket or housing 9 at 17 is the operating lever ormember 18 providedwith the cam surface 19 adapted to engage the roller20 pivoted to the arm 7 at 21. A. tension spring 1S is connected at itsone end to the arm 7 and at its other end to the member 18. Theoperating member 18 has an extension outward beyond the pivot 17, asshown at 22. Pivoted at 17 independently of the arm or operating member18 is the actuator member 23 having pivoted thereto at 24 the latch 25adapted to engage the roller 26 pivoted upon the member 22. The actuator23 is provided with a stop 27 adapted to engage the under side of thebracket ory housing 9. Pivoted to the bracket or housing 9 at 28 is asecond latch 29 adapted to engage' the roller 30 pivoted upon the member22, the rear end of the latch 29 having a jaw 31 loosely embracing thepin 32 upon the housing or bracket 9 for limiting the movement of thelatch 29, the latch 29 being held with its outer end in upward positionby a spring'VV such as 33. A tension spring 34 1s connected at its oneend to the tail 35 of the latch 25 and at its other end to the member23, urging the latch 25 in a direction to engage the roller 26.Independently pivoted at 28 is the triping member 36 having the `tail 37extendmg into the path of travel of the member 38 pivoted at 39 andcarrying the armature 40 of an electro-magnet whose' energizing coil orwinding may be connected in series in the same circuit with the mainterminals 2 and 3, so' as to trip the switch or circuit breaker uponoverload, or any other electromagnetic means may be provided to trip theswitch or circuit breaker upon the occurrence of any other predeterminedelectrical condition in the circuit including terminals 2 and 3 or inany other circuit.

In the path of the tripping member 36y is disposed the latch actuator41, ivoted at 28, the members 36 and 41 having imited movement as in thecase of latch 29. A. spring 33 holds latch actuator up, and a similarspring holds up latch 29. The tail 35 of latch 25 is disposed in thepath of travel of the actuator 41. Pivoted at 42 on the member 23 is thedog 43 whose pivotal movement on pin 42 is determined by the projections44 and 45 embracing the pin 46, upon the member 23. Screws 36a carriedby member 36 engage latch 29 and latch actuator 41.

Pivoted to the member 23 at 47 is the rod 48 connected by a turn buckleor other adjusting means 49 to the lever 50, the rod 48 being pivoted tothe lever 50 at 51, the lever 50 carrying an operators handle 52. Thelever 50 is pivoted at 53 upon the bracket 54 secured upon the cylinder55 which, in turn, is mounted upon the base or switchboard 1. Within thecylinder 55 is a longitudinally movable piston 56 with which coperatesthe rod 57 and the rod 58 passing through the glands or stuffing boxes59. As shown, the piston 56 is not secured upon either of the rods 57 or58, but actuates said rods by abutting against the same and pushingthem, the rod '57 u wardly, and the rod 58 downwardly. y thisconstruction any tendency of the piston to bind within the cylinder isavoided, such binding being more likely if the piston were secured uponthe piston rod, and where the latter passes through such a long bearingas shown on the cylinder heads. Pivoted at 60 to the bar 110 connectedwith rod 57 are the downwardly extendin 61, one on either side of thecylin er 55, which are pivoted, in turn, at 62 to the inner end of thelever 50, the latter being in two parts one on either side of thecylinder 55. Similarly, the upwardly extending links 64 are pivoted at63 to the bar 110 connected with rod 58, one link 64 on either side ofthe cylinder 55; links 64 are, in turn, pivoted to the lever 50 at 62.

On each end of the cylinder 55 is provided a valve 65, shown in sectionand elevation in Fig. 2. The nipple portion 66 screws in through thewall of the cylinder 55 and is provided with the valve seat 67 withwhich engages the valve 68 carried upon the rod 69 carrying at its upperend the head or button 70, a spring 71 intervening between the head orbutton 70 and a wall or projection within the valve, the spring 71holding the valve 68 against its seat 67. From beneath the valve seat 67there is a passage 72 communicating with the outlet passage 7 3. lViththe clearance space above the piston 56 communicates a pipe 74 whichcommunicates with the interior of the valve casing 75. Similarly,

links l with the clearance beneath the piston 56 communicates the pipe 76 which also communicates with the interior of the valve casing 75.Similarly, the supply pipe 77' and the exhaust pipe 78 communicate withthe interior of the valve casing 75. Within the casing is the valvemember 79 having the two passages or ports 80 and 81, the member 79having attached thereto a lever 82 which carries an operators handle 83.The sprin s 84 and y85 engage upon either side of te lever 83 and serveto hold the same in the central position shown. Solenoid cores orarmatures 86 and 87 are connected, respectively, by ivoted links 88 and89 to the lever 83. l ith the core or armature 86 is associated itsenergizing coil or Winding 90 and with the core or armature 87 isassociated its energizing coil or winding 91. The common terminals ofywindings 90 and 91 connect by conductor 92 with bus bar or otherconductor 93 here shown, by way of example, as the positive conductor ofa control network or circuit. The other terminal of the winding 90connects by conductor 94 with contact 99 of the operators switch D,which may be located at a more or less remote point. The switch Dcomprises the pivoted lever 100 normally held in the central positionshown, by gravity or a spring, and carries the contacts 101 and 102 inelec trical communication with each other and with the conductor 103,the latter connecting with the bus bar or conductor 104 of the samenetwork or control circuit and shown, for example, as the negativeconductor of such network or circuit. The contact 102 of the switch D isadapted to engage the Contact 107 which communicates by conductor 108with the remaining terminal of the coil or winding 91.

The valves 68 are provided for the purpose of determining with nicetythe moment when the piston 56 shall cease to exert power through switchoperating or controlling mechanism. It is desirable, to save the switchmechanism from undue strains and damage, that the power exerted thereonb the pneumatic means shall cease when suc switch mechanism has attaineda predetermined position. When the pneumatic device is moving the switchor circuit breaker mechanism to circuit closing position, it isdesirable that the neumatic power shall cease at the moment t e partsshall have reached full circuit closing position and shall have becomelatched. And it is ldesirable that the pneumatic power cease immediatelyit has operated in opposite direction to cause the actuator 23 to becomelocked and just as it becomes locked to the member 22. These valves 68determine with nicety these actions.

The operation is as follows: W'ith the switch or circuit breaker in thecircuit closing position as shown in Fig. 1, if an overload should occurin the circuit, or if any other predetermined electrical conditionshould obtain in its circuit, or in any other circuit in which the coilor winding causing the attraction of the armature 40 is connected, thearmature 40 will be attracted and rotated in a counter-clockwisedirection about its pivot 39 causin the member 38 to engage the underside o the tail 37 of the member 36 rotating the member 36 in aclockwise direction about its pivot 28, and causing screw 36a to depressthe latch 29 in opposition to spring 33, thus disengaging i the latch 29from roller 30, whereupon the operating member 18 is free to rotate in acounter-clockwise direction about its pivot 17 due to the tension of thespring 18 and due to the outward force exerted by the bridging member 6.In the downward movement of the outer end of the tripping member 36, thesecond screw 36a depresses the latch actuator 41 in opposition to secondspring 33, and 41 in turn depresses the tail 35 ofthe latch 25 inopposition to spring 34 thus releasing latch 25 from roller 26 andunlocking the member 22 i from the member 23. The member 18 is then freeto rotate about its pivot 17 independently of the member 23 and in sorotating the cam surface 19 is removed from the path of the roller 20and the arm 7 carries outwardly with it the bridging contact 6separating the same from the main terminals 2 and 3 to break thecircuit. After the bridging contact 6 has left main terminals 2 and 3the contact 14 leaves contact 10, and finally contact l5 leaves contact11, the final arcing occurring at these carbon contacts. The continuedoutward movement of the arm 7 is accompanied by th'e complete rupture ofthe circult, and in the circuit rupturing position the extension 22 onthe member 18 is in elevated position. If, now, it be desired to closethe circuit breaker again the operator at the valve 75 grasps the handle83 and rotates the same in a clockwise direction until the port 80 is incommunication with the supply pipe 77 and the pipe 74, and port 81 is incommunication with pipes 76 and 78, whereu on pressure will be exertedthrough pipe 4 to the upper end of the cylinder 55 causing the downwardtravel of piston 56 (and exhaust of air from below piston 56 throughpipes 76 and 78) and the counter-clockwise movement of the lever 5()about its pivot 53 with the consequent elevation of rod 48 and thecounter-clockwise rotation of member 23 about its pivot 17. This upwardmovement continues until the latch 25 again engages' the roller 26locking the members 22 and 23 together. At this moment the lower end ofi the screw 109, carried by the member 110 connecting the links 61, engaes the top of the button of the upper va ve 65, moving the valve 68 awayfrom lts seat 67 1n opposition to spring 61, thereby allowingcommunication through the valve and the port 73 with the outer air, thusremoving the pressure from the upper side of the pi'ston 56 androbbingthe piston of power to further raise the rod 48. Now, that theactuator 23 has become locked to the operating member 22, the operatormoves the valve handle 83 in a counter-clockwise direction, so as tobring the port or passage 81 into communication with the supply pipe 77and the pipe 76 and port 80 into communication with pipes 74 and 78,whereupon pressure will be exerted upon the under side of the piston 56causing it to rise in the cylinder 55. This upward movement of thepiston 56 causes a clockwise movement of the lever 50 about its pivot 53and the simultaneous closing of the upper valve 65, the passage 80 nowmaking connection between pipe 74 and exhaust pipe 78 allowing the airabove the piston 56 to escape through exhaust ipe 78. As the lever 50rotates in a clockwise direction about its pivot 53 the rod 48 pullsdownwardly upon the actuator 23 causing the cam surface 19 to engage theroller 20 and force the arm 7 inwardly to bring'the bridging member 6into engagement with the main terminal blocks 2 and 3 to close thecircuit, and when full circuit closing position has been reached thelatch 29 engages roller 30 to lock the parts in circuit closingposition. At this moment the upper end of the lower screw 111 engagesthe button 70 of the lower valve 65 to raise its valve 68 from its seat67 to open the lower end of the cylinder 55 to the outer atmosphere, andthe ressure on the under side of the piston 56 1s reduced, robbing thepiston of power to further 'move the parts. I f, during the closingmovement above described, the predetermined electrical condition obtainsin response to which the switch or breaker has been tripped or ou ht tobe tripped, the parts will not reach ull circuit closing positionbecause upon the attraction of the armature 40 the tail 35 of the latch25 will engage the latch actuator 41 which is held in downward positionand thereby disengage the latch 25 from roller 26 and allow the member22 and the other parts of the switch or circuit breaker to fly to opencircuit position. It is apparent` therefore, that the switch or circuitbreaker shown is of the non-closable type.

l1 it should be desired to trip the switch or circuit breakerindependently of any predetermined electrical condition, the operator atthe valve will rotate the handle 83 in a clockwise direction to connectpipe 74 with the supply pipe 77, whereupon pressure will be exertedabove the piston 56 causing it to descend and raise the rod 48 andthereby start to rotate the actuator 23 in a counter-clockwise directionabout pivot 17,

whereupon the dog 43 will ride upon the projection 43 at the outer endof the tripping member 3G depressing the same and causing the latches 29and 25 to disengage from their rollers 30 and 26, respectively, andallow the circuit breaker to fly to open circuit position.

If desired, the valve 75 may be controlled from the more or lessdistantl operators switch D. If the operator moves his lever 100 tobring contacts 102 and 107 into engagement current will flow from thepositive conductor 93 through conductor 92, coil 91, conductor 108,contact 107, contact 102, lever 100, conductor 103, to the negativeconductor 104, thereby energizing the Winding 91 and causing the core 87to move toward the right and rotate the valve so as to bring pipes 77and 7 4 into communication with each other which will cause the trippingof the circuit breaker, as above described. Or upon moving contact 101into engagement with contact 99 the coil 90 Will be energized and thecore 86 attracted toward the left to rotate the valve in acounterclockwise direction to bring supply plpe 77 into communicationwith pipe 6 to the air beneath the piston 56 to cause a closure of thecircuit breaker as above described.

What I claim is:

1. In combination, a movable contact member, an operating membertherefor, an actuator, means for locking said actuator and operatingmember together, a fluid pressure device for moving said actuator toposition to lock the same to said operating member, a valve forrendering Said fluid pressure device inert When said actuator has beenmoved to said position, and means movable in definite relation with saidactuator for actuating said valve.

2. In combination, a movable contact member, an operating membertherefor, an actuator, means for locking said actuator and operatingmember together, a doubly acting fluid pressure device for moving saidactuator in both directions, valves for rendering said fluid pressuredevice inert when said actuator has reached predetermined positions, andmeans movable in definite relation with said actuator for actuating saidvalves.

3. In combination, a movable contact member, an operating membertherefor, an actuator, means for locking said actuator and operatingmember together, a Huid pressure device for moving said actuator toposition to lock the same to said operating member, a valve forrendering said Huid pressure device inert when said actuatorhas beenmoved to said position, means movable in definite relation with saidactuator for actuating said valve, a valve controlling the fiuidsupplied to said fluid pressure device.

4. In combination, a movable contact member, an operating membertherefor, an actuator, means for locking said actuator and operatingmember together, a doubly acting Huid pressure device for moving saidactuator in both directions, valvesifor rendering said fluid pressuredevice inert when said actuator has reached predetermined positions,means movable in definite relation with said actuator for actuating saidvalves, a valve controlling the movement of said uid pressure device inboth directions, a circuit controlling said last named valve, anoperators switch biased toward normal position controlling said circuit,and means returning said last named valve to position rendering saidfluid pressure device inoperative When said operator-s switch is innormal position.

5. The combination with a non-closable circuit breaker having anoperating member and an independently movable actuator, of a singlecylinder, a piston movable in opposite directions therein, a valvecontrolling the movements of said piston in both directions, anoperative connection between said piston and said actuator, and meansfor rendering said piston inert when said actuator has been moved toposition to engage said operating member.

6. The combination with a non-closable circuit breaker having anoperating member and an independently movable actuator, of a singlefluid pressure cylinder, a piston movable in opposite directions there-1n, a connection from said piston to said actuator, a valve controllingthe movements of said piston, and a valve controlling said pistonindependently of said first mentioned valve and actuated afterpredetermined movement of said actuator.

In testimony whereof I have hereunto affixed my si nature in thepresence of the two subscribing witnesses.

WILLIAM M. SCOTT.

Witnesses:

ANNA E. STEINBOCK, ELEANOR T. MCCALL.

It is hereby certified that in Lettere Patent No. 1,147,820Vgranted July27, 1915, upon the npplication of William M. Scott, of Philadelphia,Pennsy1vnia.,"for an improvement in Electropneumatic Switches, `:inerror apRears yin the printed specication requiring correction asfollows: Page 4, line 64, claim 3, after the Word device strike out theperiod and insert a. comme.` and the Wordsl a circuit controlling said.last-named valve, an operators switch biased normal position controllingsaid circuit, and means retiirning said last-named valve to normalposition -'when said operators switch is in normal position.; and thatthe said Letters Patent should be read with .this correction thereinthat the same may conform to the record of the case in the Patent Oce.

Signed and sealed this 24th day of August, A. D., 1915.

Smm J. T. NEWTON,

Acting Commissioner of Patents.

